Acetylene nickel compounds



United States Patent 3,097,224 ACETYLENE NICKEL CONPOUNDS MichaelDnbeck, Royal Oak, Mich, assignor to Ethyl Corporation, New York, NY, acorporation of Virginia No Drawing. Filed Nov. 12, 1959, Ser. No.852,216 16 Claims. (Cl. 260-439) This invention relates to novelorganometallic compounds and their mode of preparation. Morespecifically, this invention relates to bis(cyclornatic nickel)acetylene compounds wherein each nickel atom is bonded to a cyclomatichydrocarbon group, to another nickel atom, and to an acetylene compoundwhich is bonded to both of the two nickel atoms.

It is an object of this invention to provide a novel class ofbis(cyclomatic nickel) acetylene compounds. A further object is toprovide a process for the preparation of these compounds. Another objectis to provide fuel antiknock mixtures wherein a bis(cyclomatic nickel)acetylene compound is present as a primary antiknock or as asupplemental antiknock in addition to another antiknock material.Additional objects of this invention will become apparent from a readingof the specification and claims which follow.

The objects of this invention are accomplished by pro viding compoundsrepresented by the formula:

QCE CQ CyNiNiCy' Although not bound by any theory, these compounds arebelieved to have the structural formula as follows:

In this formula, Q and Q represent either hydrogen or univalenthydrocarbon radicals containing from one to about carbon atoms. Cy andCy represent cyclomatic hydrocarbon groups which donate five electronsto the nickel atoms for bonding. By virtue of the electrons d0- nated toeach of the nickel atoms from the cyclomatic hydrocarbon groups, theacetylene molecule and the other nickel atom, each of the nickel atomspresent in the compounds of my invention, achieves the inert gaselectron configuration of krypton.

The cyclomatic hydrocarbon groups, designated by the symbols Cy and Cyin the above formula, may be the same or different and arecyclopentadienyl-type hydrocarbon radicals. By this, it is meant thatthe radical contains the cyclopentadienyl moiety. In general, suchcyclomatic hydrocarbon groups can be represented by the formulae:

wherein the Rs are selected from the group consisting of hydrogen andunivalent hydrocarbon radicals.

A preferred class of cyclomatic radicals suitable in the practiceXof myinvention are those which contain from five to about 13 carbon atoms.These are exemplified by cyclopentadienyl, indenyl,methylcyclopentadienyl, propylcyclopentadienyl, diethylcyclopentadienyl,phenylcyclo pentadienyl, tert-butyl cyclopentadienyl, p-ethylphenylcyclopentadienyl, 4-tert-butyl indenyl and the like. The compounds whichyield these radicals are preferred as they are the more readilyavailable cyclomatic compounds, and the compounds of my inventioncontaining these radicals have the more desirable physicalcharacteristics which render them of superior utility.

3,097,224 Patented July 9, 1963 ice As shown in the above formula, thebridging acetylenetype molecule is believed to be bonded to both of thenickel atoms in forming the compounds of my invention. As visualized,the triple bond in the bridging acetylenic compound is reduced to asingle bond thus making four electrons available for bonding to the twonickel atoms. Each of the carbon atoms on either side of the triple bondis thereby bonded to each of the nickel atoms. The actual configurationof the bridging acetylenic molecule is believed to be approximately atright angles to the plane in which the two inter-connected nickel atomslie. This is shown in the above formula by means of the dotted linesindicating bonding of the carbon atom which is behind the plane of thepaper to the two nickel atoms illustrated as lying in the plane of thepaper. The other carbon atom which is bonded to the two nickel atoms isdepicted as lying in front of the plane of the paper. Thus, the bondsbetween this carbon atom and the two nickel atoms are drawn as solidlines.

The substituent groups Q and Q, as shown in the above formula, may bethe same or different and are hydrogen or univalent hydrocarbon groupscontaining from one to about 10 carbon atoms. Q and Q are preferablyalkyl groups such as methyl, ethyl, propyl, butyl, amyl, octyl or decyl,including normal alkyls or branched chain alkyls. Preferably, Q and Q,if an alkyl group, contains from one to about six carbon atoms sincealkyl radicals within this range impart desirable physical properties tothe compounds of my invention.

Q and Q may also be an aryl radical, either a fused or single ring, suchas phenyl, tolyl, xylyl, naphthyl or the like. In addition, Q and Q maybe hydrocarbon groups containing unsatuarted double bonds such -asalkenyl or cycloalkenyl radicals. Typical of such radicals are butenyl,pentenyl, hexenyl, nonenyl, cyclohexenyl, cyclopentenyl and the like. Inaddition, the Q groups may be alkaryl radicals, ar-alkyl radicals, andcycloal-kyl radicals containing up to about 10 carbon atoms. Typical ofsuch radicals are benzyl, phenylethyl, phenylpropyl, phenylbutyl,cyclohexyl, cyclopentyl, cycloheptyl, cyclodecyl, p-ethylphenyl,rn-butylphenyl, p-methylphenyl and the like.

Although the Q groups, as defined above, are univalent hydrocarbonradicals or hydrogen, these groups may be substituted with polarsubstituents which preferably should be separated by at least two carbonatoms from the triple acetylenic bond to avoid cumbersome sidereactions. Typ ical acetylenic compounds containing such non-reactivenon-hydrocarbon substituent groups are perhalo butynes, propargylalcohol, ethynyl cyclohexanol, beta carboxy esters of the butynes,pentynes, hexynes, and heptynes, 5- methoxy pentyne-l, and the like.

The method by which my compounds are formed involves the followingchemical reaction:

QCE C-Q Cy Ni QCECQ CyNi-NiCy This reaction may, in general, be carriedout between room temperature and about 150 C. Preferably, however, thereaction is carried out between about 60 to about C. since within thisrange yields are maximized and undesirable side reactions are minimized.

The pressure at which the reaction is carried out is, in general, notcritical. If the acetylenic reactant is a gas, however, the pressureshould be sufficiently high to insure that a goodly percentage of thegaseous acetylenic reactant is dissolved in the solution comprising thebis(cyclornatic) nickel reactant and a solvent. Since it is necessaryfor the gaseous acetylenic reactant to contact the his (cyclomatic)nickel compound in order for reaction to take place, pressure will, inthis instance, have a substantial effect on the reaction rate. Ingeneral, pressures between about atmospheric and about 10,000 p.s.i.g.may be employed. If the acetylenic reactant is acetylby the use ofhigher pressure.

The reaction is generally canried out in the presence of a solventalthough in certain cases the acetylenic reactant, if used in excess,may serve as the solvent. -In general, any unreactive solvent in whichthe bis- (cyclomatic) nickel compound is fairly soluble may be employed.Typical of such solvents are high boiling saturated hydrocarbons such asn-octane, n-decane, and other parafiinic hydrocarbons having up to about20 carbon atoms such as eicosane, pentadecane and the like. Alsoapplicable are aromatic solvents such as benzene, toluene, mesitylene,and the like. Typical ether sol vents are ethyl octyl ether, ethyl hexylether, diethylene glycol methyl ether, diethylene glycol diethyl ether,diethylene glycol dibutyl ether, ethylene glycol dimethyl ether,ethylene glycol diethyl ether, trioxane, tetrahydrofuran, ethyleneglycol dibutyl ether and the like. Ester solvents which may be employedinclude pen-tyl butanoate, ethyl decanoate, ethyl hexanoate, and thelike. Silicone oils such as the dimethyl polysiloxanes,-bis(chlorophenyl) polysiloxanes, hexapropyldisilane, anddiethyldipropyldiphenyldisilane may also be employed. Other estersolvents are those derived from succinic, glu-taric, adipic,

I pimelic, suberic, azelaic, sebacic and pinic acids. Specific examplesof such esters are di-(Z-ethylhexyl) adipate, di-

-(2-ethylhexyl) azelate, di-(Z-ethylhexyl) sebacate, di-

(methylcyclohexyl) adipate and the like. Preferred solvents are thepolar ethers such as diethylene glycol dimethyl ether andtetrahydrofuran.

A further criteria for the solvent is that it !be one which is easilyseparable from the compounds formed in the process. If, for example, theproduct is a liquid as in the case of his (cyclopentadienyl nickel)hexyne-3, the I solvent should be selected so that it has a normalboiling lization.

The time required for my process will vary in accord- I It generallyhours, howmore expensive bis(cyclomatic) nickel reactant, it ispreferable in my process to use excess quantities of the acetylenicreactant. In general, I employ from about 0.75 to about 30 moles ofacetylenic reactant for each mole of bis(cyclomatic) nickel reactant.Higher or lower quantities of the acetylenic reactant may be used but,in general, I find that quantities within this range insure a relativelyhigh yield of product.

As previously set forth, my invention embraces a variety of bis(cyclomatic nickel) acetylenic compounds. Typical of these compounds arebis(cyclopentadienyl nickel) acetylene, bis(cyclopentadienyl nickel)propyne, !bis(cyclopentadienyl nickel) pentyne-l, bis(cyclopentadienylnickel) bu-tyne-l, bis(cycl0pentadienyl nickel) phenyla'cetylene,bis(cyclopentadienyl nickel) diphenyl- V culated for acetylene,bis(cyclopentadienyl nickel) butyne-Z, bis- (cyclopentadienyl nickel)hexyne-3, bis(cyclopentadienyl nickel) perfluorobutylene-Z,bis(cyclopentadienyl nickel) decyne-S, bis (methylcyclopentadienylnickel) octyne-4, bis(indenyl nickel) hexyne-l, bis(cyclopentadienylnickel) octodecyne-9, bis(cyclopentadienyl nickel) propargyl alcohol,cyclopentadienyl nic'kel methyl cyclopentadienyl nickel hexyne-3, andthe like.

Preferably, the process is carried out under a protective atmosphere ofan inert gas such as nitrogen, helium, argon and the like. This preventsdecomposition of the reactants and/or products and results in theobtaining of higher yields.

To further illustrate my compounds and their mode of preparation, thereare presented the following examples in which all parts and percentagesare by weight unless otherwise indicated.

anhydrous tetrahydrofuran to form a solution which was sealed in astainless steel autoclave. Acetylene was added to the autoclave until anequilibrium pressure of 100 p.s.i.g. was attained over the solution. Theautoclave was then pressurized to 2,000 p.s.i.g. with pure nitrogen. Thereaction mixture was heated for two and one-half hours at C. and allowedto cool overnight. It was then discharged from the autoclave undernitrogen. On filtering, two parts of amorphous decomposition product wasseparated from the reaction mixture. The solvent was then removed fromthe remaining reaction mixture under reduced pressure to leave adarkgreen residue. The residue was triturated with a small volume ofpetroleum ether to remove oil-like contaminants, and the residue wassublimed at 0.05 mm. Hg and room temperature to give 12 parts ofnickelocene having a melting point of 172173 C. When sublimationappeared to have ceased, the temperature was raised to 60 C. This causedfurther sublimation to yield a dank-green solid sublimate. Repeatedfractional sublimation followed by recrystallization from petroleumether yielded 0.5 part of a flaky, light-green lustrous solid having amelting point of 143 C. This solid was analyzed and found to be-bis(cyclopentadienyl nickel) acetylene.

Analysis-Found: C, 52.3; H, 4.49; Ni, 42.6. Cal- (C H Nl) HCECHI C,52.7; H, 4.39; Ni, 42.9. 7

EXAMPLE II was cooled. The reaction product was filtered to remove someblack decomposition product. The black decomposition product wasthoroughly washed with low-boiling petroleum ether and the washings werekept separate from the filtrate. The filtrate was cooled to 70 C.

yielding green crystals which were filtered off under nitrogen andwashed with cold petroleum ether. The washed crystals were then sublimedat 0.05 mm. Hg and room temperature to give three parts of nickelocenehaving a melting point of 172l73 C. When the nickelocene had ceased tosublime, the temperature of the sublimator was raised to 60 C. whichcaused the sublimation of 0.7 part of a dark-green solid. This solid wasrecrystallized from petroleum ether to yield flaky green crystals havinga melting point of 142143 C. with decomposition. An additional 3.1 partsof nickelocene and 0.3 part of the flaky green crystals melting at 143C. were recovered from the dimethyl carbitol filtrate by dilution withwater, extraction with benzene and fractional sublimation. Evaporationof the petroleum ether washings followed by fractional sublimationyielded an additional 1.0 part of nickelocene and 0.2 part of product.On analysis, the flaky green crystals melting at 142-143 C. were foundto be bis(cyclopentadienyl nickel) acetylene. The total yield of thiscompound was 1.2 parts.

EXAMPLE III To 704 parts of benzene were added 20 parts of nickeloceneto form a solution which was charged to a stainless steel autoclave. Toautoclave was then pressurized with commercial grade acetylene to anequilibrium pressure of about 100 p.s.i.g. The autoclave was thenpressurized to 2,000 p.s.i.g. with pure nitrogen and heated at 85 C. forsix hours. On discharge, filtration of the reaction mixture yieldedabout 34 parts of a black nickelcontaining intractable solid. Removal ofthe solvent from the filtrate under reduced pressure and roomtemperature gave a brown residue which was triturated with about 320parts of low-boiling petroleum ether. Removal of the ether solventfollowed by repeated fractional sublimation of the residue andrecrystallization of the dark-green condensate from petroleum etheryielded about 0.3 part of a flaky green solid having a melting point of142143 C. with decomposition. This product was found to have an infraredspectrum which was identical to the infrared spectrum ofbis(cyclopentadienyl nickel) acetylene as prepared in the previousexamples. This proved conclusively that the product obtained wasbis(cyclopentadienyl nickel) acetylene.

EXAMPLE IV A solution comprising 20 parts of nickelocene in 710 parts oftetrahydrofuran was charged to a stainless steel autoclave. Theautoclave was pressurized to an equilib rium pressure of 85 p.s.i.g.with acetylene, and the reaction mixture was heated at 45 C. forapproximately 100 hours. The autoclave Was discharged, and the reactionmixture was filtered. Excess solvent was stripped off under reducedpressure without heating. The green crystalline fractions, whichseparated as the volume of the solution and the temperature decreased,were filtered under nitrogen and fractionally sublimed at 0.05 mm. Hg. Atotal of 12.6 parts of unreacted nickelocene and 1.2 parts ofbis(cyclopentadienyl nickel) acetylene were isolated. Thebis(cyclopentadienyl nickel) acetylene had a melting point of 14l-142 C.and was identical to the bis(cyclopentadienyl nickel) acetylene asprepared in the previous examples.

EXAMPLE V A solution comprising 20 parts of nickelocene dissolved in 622parts of anhydrous tetrahydrofuran was charged to a stainless steelautoclave along with 100 parts of propyne. The reaction mixture washeated at 85 C. for four and one-half hours after which the reactionvessel was cooled to room temperature. The vessel was then discharged,and the reaction product was filtered. The solvent was removed at roomtemperature under reduced pressure, and the dark-green residues weretriturated with approximately 38.4 parts of petroleum ether andfiltered. Sublimation of the triturate residues at room temperature and0.05 mm. Hg yielded 11 parts of nickelocene. The petroleum ethersolubles from the sublimation residues were combined with the dark-greentriturate liquors and the whole was chromatographed on alumina andeluted with petroleum ether. This procedure enabled separation of adarkagreen crystalline solid from small amounts of nickelocene in theeluate. Repeated chromatognaphy of the dark-green solid followed byfractional sublimation yielded 2.1 parts of dark-green needle-likecrystals having a melting point of 68-69 C. which on Four parts ofnickelocene, seven parts of 3-hexyne and 8.9 parts of tetrahydrofuranwere charged to a reaction vessel and heated at 100 C. for 15 hours. Thereaction vessel was then cooled and discharged. Excess tetrahydrofuranwas removed under reduced pressure at room temperature. The dark-greenoily residue was dissolved in petroleum ether and chromatographed onalumina. Elution with petroleum ether gave poor resolution of thedark-green product band from traces of unreacted nickelocene. Removal ofexcess petroleum ether from the center cut of the dark-green productband yielded a light-green residue which was evaporatively distilled at0.05 mm. Hg and 50 C. Repeated chromatographic purification followed byevaporative distillation failed to cause crystallization at roomtemperature. The darkgreen liquid possessed infrared absorbencies in thenine to 13 micron regions characteristic of bis(cyclopentadienyl nickel)acetylene. On analysis, the dark-green liquid product (2.4 parts) wasfound to be his (cyclopentadienyl nickel) hexyne-3.

Analysis.Found: C, 58.6; H, 6.21; Ni, 35.4. Calculated for (C H Ni) C HCECC H C, 58.3; H, 6.10; Ni, 35.6 percent.

EXAMPLE V11 T0 18 parts of nickelocene and 534 parts of tetrahydrofuranin an autoclave was added sufficient acetylene to raise the equilibriumpressure to 180 p.s.i.g. The reaction mixture was heated for 16 hours atC. The autoiclave was then discharged, and the reaction product wasfiltered. The solvent was removed at room temperature under reducedpressure. The green residue was triturated with about 64 parts ofpetroleum ether to remove oily contaminants. The residue was thenfractionally sublimed at 0.01 mm. Hg. During the sublimation, unreactednickelocene was sublimed at room temperature whereas the product,bis(cyclopentadienyl nickel) acetylene, required a sublimationtemperature of 60 C. Additional nickelocene and product was alsoisolated from the petroleum ether triturates by means of chromatographyon alumina. The total yield of bis(cyclopentadienyl nickel) acetylene,having a melting point of l42-143 C., was 6.3 parts which corresponds toa yield of 71 percent.

EXAMPLE VIII Five parts of nickelocene, 10 parts of l-pentyne and 13.3parts of tetrahydrofurasn were charged to a sealed reaction vessel andheated at C. for 17 hours. The reaction vessel was discharged undernitrogen, and the solvent was stripped from the reaction product underreduced pressure Sublimation of the crude reaction residue at 0.05 mm.Hg and 60 C. resulted in the isolation of a dark-green liquid whichslowly crystallized. Chromatographic purification of the material onalumina, using petroleum ether eluant, removed traces of an oilycontaminant. Resublimation of the chromatographed solid gave 1.1 partsof bis(cyclopentadienyl nickel) l-pentyne which was a dark-green solidhaving a melting point of 505l C. On analysis, there was found: C, 56.4;H, Calculated for (C5H5ND2HCECC3H7: C, 57.0; H, 5.80; Ni, 37.2 percent.

EXAMPLE IX Fifteen parts of nickelocene and 32 parts of Z-butyne weredissolved in 534 parts of tetrahydrofuran. The solution was charged to astainless steel autoclave and heated at C. for 20 hours. The autoclavewas then cooled, and the reaction product was discharged. The re actionproduct was filtered, and solvent was removed under reduced pressure.The green reaction residue was vessel at 120 C. for 10 hours. movedunder reduced pressure, and the residue is taken 1 up in low-boilingpetroleum ether, chromatographed on EXAMPLE X A solution of 5.0 parts ofnickelocene and 10 parts of ethynyl benzene in 26.6 parts oftetrahydrofuran was heated at reflux for 30 minutes under a protectiveatmosphere of nitrogen. The solvent and unreacted ethynyl benzene werethen removed under reduced pressure, and the reaction residue wastriturated with low-boiling petroleum ether. The triturates werechromatographed on alumina and eluted with petroleum ether. Thisprocedure yielded one part of unreacted nickelocene. The remainingreaction residues were fractionally sublimed at 0.05

Hg, and an additional 1.5 parts of unreacted nickelocene was obtained.On increasing the temperature of the sublimator to 60 C., there wasobtained 0.8 part 'of bis(cyclopentadienyl nickel) phenylacetylene whichwas a dark-green solid that crystallized rrorn isooctane as dark-greenneedles having a melting point of 132 C. On analysis, there was found:C, 61.2; H, 4.6; Ni, 33.3. Calculated for (C5H5Nl) HCECC H5I C, 61.8; H,4.6; Ni, 33.5 percent.

EXAMPLE XI A solution of two parts of nickelocene and two parts ofperfluorobutyne-Z in 20 parts of tetrahydrofuran was allowed to stand atroom temperature for 70 hours. The viscous reaction mixture was relievedof the volatile solvent at reduced pressures, and the residue wassublimed at 0.02 mm. Hg and 40 C. The sublimate was triturated withlow-boiling petroleum ether, and the triturates were chromatographed onalumina and eluted with petroleum ether. This procedure resulted in therecovery of 1.2 parts of nickelocene and 0.05 part of a dark-greencrystalline material having a melting point of 93 C. This product wasidentified as bis(cyclopentadienyl nickel) perfluorobutyne-Z through itselemental analysis and a comparison of its infrared spectrum with thesimilar infrared spectra of other bis(cyclopentadienyl nickel) alkynecompounds of my invention.

EXAMPLE XII A solution of four parts of nickelocene and three parts ofdiphenylacetylene in 50 parts of toluene was refluxed for 10 hours.Excess solvent was removed under reduced pressure, and unreactednickelocene and diphenylacetylene were sublimed out of the reactionmixture under reduced pressures at 50 C. The residue was triturated withpetroleum ether, and the triturate was filtered and chilled to Dry Icetemperatures where crystallization occurred. On recrystallization frompetroleum ether, there Was obtained one part of bis(cyclopentadienylnickel) diphenylacetylene having a melting point of 148 C. The compoundwas. clearly identified as bis(cyclopentadienyl nickel)diphenylacetylene through means of an elemental analysis and theinfrared spectrum of the compound which closely resembled those of myother 'bis(cyclopentadienyl nickel) alkyne compounds;

EXAMPLE XIII A solution of 0.2 mole of nickelocene and 0.15 mole ofdecyne-S is dissolved in isooctane and heated in a sealed Excess solventis realumina, and eluted with petroleum ether. This results in a goodyield of bis(cyclopentadienyl nickel) decyne-S with an infrared spectrumcharacteristic of the bis(cyclopentadienyl nickel) alkyne compounds.

EXAMPLE XIV This enables the. isolation of a good yield of bis(methylcyclopentadienyl nickel) oc-tyne-4 with an infrared spectrumcharacteristic of the bis(cyclopentadienyl nickel) alkyne compounds.

EXAMPLE XV A solution of 0.05 mole of his (indenyl) nickel and 1.5 molesof hexyne-l is heated in a closed vessel at C. for 10 hours. Excesshexyne-l is removed under reduced pressure, and the residue is taken upin petroleum ether and chromatographed on alumina and eluted withpetroleum ether. A good yield of bis(indenyl nickel) hexyne-l isobtained.

A further embodiment of the present invention comprises the use of thecompounds of my invention as antiknock agents in a liquid hydrocarbonfuel used in spark ignition internal combustion engines. For this use, Iprovide a liquid hydrocarbon fuel of the gasoline boiling rangecontaining from about 0.05 to about 10 grams per gallon of nickel as acompound of my invention. It is found that these compositions, whenemployed as fuels for a spark ignition internal combustion engine,greatly reduce the tendency of. the engine to knock.

A preferred composition of my invention comprises a hydrocarbon of thegasoline boiling range containing from about 1.0 to about 6.0 grams ofmetal per gallon of fuel as a nickel compound as defined previously.This range of metal concentration is preferred since it is found thatsuperior fuels result from its employment.

A further preferred class of compositions of my invention compriseshydrocarbon fuels containing a bis(cyclomatic nickel) acetyleniccompound wherein the bridging acetylenic group contains from four to 10carbon atoms. A still further preferred class of compositions are thosein which the bridging acetylenic group contains six carbon atoms. A mostpreferred composition is that containing bis(cyclomatic nickel) hexyne-3since these compounds are found to be most excellent antiknockadditives.

The base fuels used to prepare the compositions of my invention have aWide variation of compositions. They generally are petroleumhydrocarbons and are usually blends of two or more components containinga mixture of many individual hydrocarbon compounds.

' These fuels can contain all types of hydrocarbons, in-

- chains; and aromatics containing aliphatic side chains.

The fuel type depends on the base stock from which it is obtained and onthe method of refining. For example, it can be a straight run orprocessed hydrocarbon, includnig thermally cracked, catalyticallycracked, refer-med fractions, etc. When used for spark-fired engines,the boiling range of the components in gasoline can vary from zero toabout 430 'F., although the boiling range of the fuel blend is oftenfound to be between an initial boiling point of from about 80 F. to F.and a final boiling point of about 430 F. While the above is true forordinary gasoline, the boiling range is somewhat more restricted in thecase .of aviation gasoline. Specifications for the latter often call fora boiling range of from about impurities. One such impurity is sulfur,which can be present either in a combined form as an organic orinorganic compound, or as elemental sulfur. The amounts of such sulfurcan vary in various fuels about 0.003 percent to about 0.30 percent byweight. Fuels containing quantities of sulfur, both lesser and greaterthan the range of amounts referred to above, are also known. These fuelsalso often contain added chemicals in the nature of antioxidants, rustinhibitors, dyes, and the like.

The bis(cyclomatic nickel) acetylenic compounds of my invention can beadded directly to the hydrocarbon fuel, and the mixture then subjectedto stirring, mixing or other means of agitation until a homogeneousfluid results. In addition to the bis(cyclornatic nickel) acetyleniccompounds, the fuel may have added thereto antioxidants, metaldeactiva-to-rs, halohydrocarbon scavengers, phosphorus compounds,anti-rust and anti-icing agents, and supplementary wear inhibitors. Thefollowing examples are illustrative of improved fuels of improved fuelsof my invention containing a lbis(cyclornatic nickel) acetyleniccompound, and also a method for preparing said improved fuels.

EXAMPLE XVI To a synthetic fuel consisting of 20 volume percent toluene,20 volume percent isobutylene, 20 volume percent isooctane and 40 volumepercent n-heptane is added :bis(cyclopentadienyl nickel) hexyne-3 inamount such that the nickel concentration is 0.05 gram per gallon. Themixture is agitated until a homogeneous blend of the bis-(cyclopentadienyl nickel) hexyne-3 compound in the fuel is achieved.This fuel has substantially increased octane value.

EXAMPLE XVII To 1000 gallons of commercial gasoline having a gravity of59.0" API, an initial boiling point of 98 F. and a final boiling pointof 390 P. which contains 45.2 volume percent paraffins, 28.4 volumepercent olefins and 25.4 volume percent aromatics is added 10.0 gramsper gallon of nickel as bis(cyclopentadienyl nickel) pentyne- 1 to givea fuel of enhanced octane quality.

EXAMPLE XVIII Bis(cyclopentadienyl nickel) diphenylacetylene is added inamount sufficient to give a nickel concentration of 6.0 grams per gallonto a gasoline having an initial boiling point of 93 F., a final boilingpoint of 378 F. and an API gravity of 562.

EXAMPLE XIX To a liquid hydrocarbon fuel containing 49.9 volume percentparaflins, 15.9 volume percent olefins and 34.2 volume percent aromaticsand which has an API gravity of 51.5, an initial boiling point of 11 F.and a final boiling point of 394 F. is added Ibis(cycl-opentadienylnickel) acetylene to a nickel concentration of 3.0 grams per gallon.

EXAMPLE XX To the fuel of Example XIX is added bis(indenyl nickel)decyne-3 in amount such that the nickel concentration is 2.0 grams pergallon.

A further embodiment of the present invention comprises a liquidhydrocarbon fuel of the gasoline boiling range containing an organoleadantiknock agent and in addition a bis(cyclomatic nickel) acetyleniccompound as defined previously. In this embodiment of the invention, itis often desirable that the fuel contain also conventionalhalohydrocanbon scavengers or corrective agents as conventionally usedwith organolead antiknock agents. When an organolead antiknock agent isemployed, it may be present in the fuel in concentrations up to abouteight grams of lead per gallon. In the case of aviation fuels, up to6.34 grams of lead may be employed.

For each gram of lead, there may be present from about 0.008 to aboutgrains of nickel as a bis(cyclornatic 10 nickel) acetylenic compound. Apreferred range comprises those compositions containing from about 0.1to about six grams of nickel as a bis(cyclomatic nickel) acetyleniccompound for each gram of lead as an organolead compound.

A preferred embodiment of my invention comprises a liquid hydrocarbonfuel of the gasoline boiling range containing from about 0.5 to about6.34 grams of lead per gallon as an organolead an-tiknock agent and fromabout 0.008 to about one gram of nickel per gallon as a bis(cyclomaticnickel) acetylenic compound as defined above. A further preferred aspectof my invention com prises compositions, as defined previously, in whichthe nickel concentration ranges from about 0.01 to about 0.5

and most preferably from about 0.01 to about 0.3 gram of nickel pergallon. These ranges of metal concentrations are preferred as it has:been found that especially superior fuelsparticularly from acost-effectiveness standpoint-result from their use.

A most preferred aspect of my invention comprises leaded fuelscontaining a bis(cyclomatic nickel) acetylenic compound, as definedpreviously, in which the bridging acetylenic group contains from four toabout 10 carbon atoms. Most preferably, the bridging acetylenic groupcontains six carbon atoms as in the specific compound, bis(cyclopentadienyl nickel) hexyne-3. These compounds are preferred sincethey have the requisite volatility and solubility in gasoline to makethem easily inducted into an internal combustion engine.

The organolead ant-iknock agents are ordinarily hydrocarb-oleadcompounds including tetraphenyllead, dimethyldiphenyllead,tetrapropyllead, dimet-hyldiethyllead, tetrarnethyllead and the like.Tetraethyllead is preferred as it is most commonly available as acommercial antiknock agent. It is also convenient in the case whereorganolead antiknock agents are employed to premix into a fluid thebis(cyclomatic nickel) acetylene compound, the organolead an-tiknockagent and supplementary agents, such as scavengers, antioxidants, dyesand solvents, which ffuids are later added to the liquid hydrocarbonfuel to be improved.

Where halohydrocalrbon compounds are employed as scavenging agents, theamounts of halogen used are given in terms of theories of halogen. Atheory of halogen is defined as the amount of halogen which is necessaryto react completely with the metal present in the antiknock mixture toconvert it to the metal dihalide, as for example, lead dihalide. Inother words, a theory of halogen represents two atoms of halogen forevery atom of lead present. In like manner, a theory of phosphorus isthe amount of phosphorus required to convert the lead present to leadorth-ophosphate, Pb (PO that is, a theory of phosphorus represents twoatoms of phosphorus for every three atoms of lead. One theory ofarsensic, antimony and bismuth is defined in the same general way. Thatis, one theory thereof is two atoms of the element per each three atomsof lead.

The hal-ohydrocarbon scavengers which can be employed in thecompositions of this invention can be either aliphatic or aromatichalohydrocarbons tor a combination of the two having halogen attached tocarbon in either the aliphatic or aromatic portion of the molecule. Thescavengers may also be carbon, hydrogen and oxygen containing compounds,such as haloalkyl ethers, halohydrins, halo ethers, halonitro compounds,and the like. Still other examples of scavengers that may be used in thefuels of this invention are illustrated in US. Patents 1,592,954;1,668,022; 2,398,281; 2,479,900; 2,479,901; 2,479,902; 2,479,903;2,496,983; 2,661,379; 2,822,252; 2,849,302; 2,849,303; and 2,849,304.Mixtures of different scavengers may also be used and other scavengersand modifying agents, such as phosphorus compounds, may also beincluded. Concentrations of organic halide scavengers ranging from about0.5 to about 2.5 theories I given in U.S. Patent 2,398,381.

, invention.

When used in the compositions of this invention, phosphorus, arsensic,antimony and bismuth compounds have the property of altering enginedeposit characteristics in sevenal helpful Ways. Thus, benefits areachieved by including in the compositions of this invention one or moregasoline-soluble organic compounds of the elements of. Group VA of theperiodic table, which elements have atomic numbers 15 through 83. Theperiodic table to which reference is made is found in Langes Handbook ofChemistry, 7th Edition, pages 58-59. One efiect of these Group VAcompounds is to alter the deposits so that in the case of spark plugsthe resulting deposits are less conductive. Thus, imparted to the sparkplug is greater resistance to fouling. In the case of combustion chambersurface deposits, the Group VA element renders these deposits lesscatalytic with respect to hydrocarbon oxidation and thus reduces surfaceignition. In addition, these Group VA elements in some Way inhibitdeposit build up on combustion chamber surfaces, notably exhaust valves.This beneficial efiect insures excellent engine durability. Inparticular, excellent exhaust valve life is assured. Of these Group VAelements the use of gasoline-soluble phosphorus compounds is preferredfrom the oost-efiectiveness standpoint. Applicable phosphorus additivesinclude the general organic phosphorus compounds, such as derivatives ofphosphoric and phosphorus acids. Representative examples of thesecompounds include trimethylphosphate, ltrimethylphosphite,phenyldimethylphosphate, triphenylphosphate, tricresylphosphate,tri-B-chloropropyl thionophospha-te, tributoxyethy'lphosphate, xylyldimethylphosphate, and other alkyl, aryl, aralkyl, alkaryl andcycloalkyl analogues and homologues of these compounds.Phenyldimethylphosphates in which the phenyl group is substituted withup to three methyl radicals are particularly preferred because theyexhibit essentially no antagonistic effects upon octane quality duringengine combustion. Other suitable phosphorus compounds are exemplifiedby dixyly-l phosphoramidate, tributylphosphine, triphenylphosphineoxide, t-ricresyl thiophosphate, cresyldiphenyl phosphate, and the like.Gasoline-soluble compounds of arsensic, antimony and bismuthcorresponding to the above phosphorus compounds are likewise useful inthis respect. Thus, use can be made of various alkyl, cycloaikyl,aralkyl, aryl land/or alkaryl, arsenates, arsenites, antimonates,antimonites, bismuthates, bismuthites, etc. Tricresyl arsenite,rtricumenyl arsenate, trioctyl antimonate, triethyl antimonite,d-iethylphenyl bismuthate and the like serve as examples. Other veryuseful arsensic, antimony and bismuth compounds include methyl arsine,rtrimethyl arsine, triethyl arsine, triphenyl arsine, arseno benzene,triisopropyl bismuth-inc, tripentyl stibine, tricresyl stibine, trixylylbismuthine, tricyclohexyl bismuthine and phenyl dicresyl bismuthine.From the gasoline solubility and engine inductibility standpoints, or-

ganic compounds of these Group VA elements having up to about 30 carbonatoms in the molecule are preferable. Concentrations of these Group VAcompounds ranging fnom about 0.05 to about one theory based on the leadnormally sufiice. In other Words, the foregoing technical benefits areachieved when the atom ratio of Group VA element-to-lead ranges fromabout 0.123 to about 2:3.

A further embodiment of my invention comprises antiknock fluidscontaining [an organolead antiknock agent, a bis(cyclomatic nickel)acetylenic compound, and, optionally, a scavenger for the organoleadcompound. The quantities of nickel compound and scavenger present withrespect to the quantity of lead present are the same as set forth in thepreceding paragraphs in describing a hydrocarbon fuel containing thesevarious components. Thus, thefluid can be blended with a hydrocarbonbase fuel to i give the fuel compositions described above.

The following examples are illustrative of fuels and fluids containingorganolead compounds in combination with various bis(cyclomatic nickel)acetylene compounds.

EXAMPLE XXI To 10-00 gallons of a gasoline containing 46.2 percentparaflins, 28.4 percent olefins, and 25.4 percent aromatics which has afinal boiling point of 390 F. and an API gnavity of 59.0 and whichcontains three milliliters of tetraethyllead as 62Mix (1 theory ofethylene dichloride and 0.5 theory of ethylene dibromide) is addedsufficient bis(cyclopentadienyl nickel) pentyne-l to give a nickelconcentration of six grams per gallon.

EXAMPLE XXII To a typical aviation fuel having an API gravity of 64.4and an end boiling point of 335 F. and which contains 8.0 grams oftetraethyllead and one theory of dibromobutane is added a mixture ofbis(cyclopentadienyl nickel) pentyne-l and bis(cyclopentadienyl nickel)hexyne-3 in amounts such that two grams of nickel from the pentyne-lcompound and one gram of nickel from the hexyne-3 compound are presentin the finished fuel.

EXAMPLE XXIII A fluid for addition to gasoline is prepared by admixingtetraethyllead, bis(cyclopentadienyl nickel) hexyne-3 and trimethylphosphate in amount such that for each gram of lead there is 0.01 gramof nickel and 0.1 theory of trimethylphosphate.

To demonstrate the etfectiveness of hydrocarbon fuels blended withbis(cyclomatic nickel) acetylene compounds according to the invention,tests 'were made on fuels to -Which no antiknock agent Was added andfuels which were blended in accordance with this invention. These testswere conducted according to the Research Method. The Research Method ofdetermining octane number of a fuel is generally accepted as a method oftest which gives a good indication of fuel behavior in full scaleautomotive engines under normal driving conditions and is the methodmost used by commercial installations in determining the value of agasoline additive. The Research Method of testing antiknocks isconducted in a single cylinder engine especially designed for thispurpose and referred to as the CFR engine. This engine has a variablecompression ratio and during the test the temperature of the jacketWater is maintained at 212 F. and the inlet air temperature iscontrolled at =125 F. The engine is operated at a speed of 600 rpm. witha spark advance of 13 before top dead center. The test method employedis more fully described in Test Procedure D- 908-55 contained in the1956 edition of ASTM Manual of Engine Test Methods for Rating Fuels.When tested in this manner, it is found that the addition of one gram ofnickel per gallon as the compound, bis(cyclopentadienyl nickel)hexyne-3, causes a substantial increase in the octane number of anon-additive containing gasoline. Further tests which were performedusing the Research Method involved the base reference fuels whichcontained both a lead antiknock and halohydrocarbon scavengers. To thereference fuels was added a typical compound of my invention,bis(cyclopentadienyl nickel) hexyne-3. In each case, a substantial gainin the octane number of the base fuel was noted.

These results are set forth in the following table. The i a fueldesignated as A in the table comprised 40 percent by volume of toluene,30 percent by volume of n-heptane, 20 percent by volume ofdiisobutylene, and 10 volume percent isooctane containing threemilliliters of tetraethyllead per gallon as 62-mix. 62-mix is acommercial antiknock fluid comprising tetraethyllead, 1.0 theory ofethylt enedichloride and 0.5 theory of ethylene dibromide. The t 13 fueldesignated as B is a commercial regular grade fuel containing threemilliliters of tetraethyllead per gallon as 62-mix, and the fuelsdesignated C, D, E and F are commercial premium grade fuels containingthree milliliters per gallon of tetraethyllead as 62-mix.

Table I.Research Octane Number vs. Fuel Type Similar results areobtained using concentrations of the nickel additive up to grams ofnickel for each gram of lead in the fuel. Also, good results areobtained using other of the nickel compounds of my invention as theantiknock additive.

As shown by the above data, a typical compound of my invention,bis(cyclopentadienyl nickel) hexyne-3, is a very effective supplementalantiknock. As in the case of most supplemental antiknocks, it isgenerally more effective as a supplement at low concentrations, and itseifectiveness is diminished as its concentration is increased.

Further tests were conducted in a slightly modified version of thesingle cylinder CFR engine described above. In the modified testversion, the fuel is injected directly into the engine cylinder ratherthan being inducted via a carburetor. In addition, the fuel iscontinually recirculated prior to injection into the cylinder so as tominimize any precipitation of the additive from the fuel. In thismodified test, the single cylinder CFR engine is operated under thefollowing conditions:

When tested in the above manner in the modified CFR injector engine, thefollowing results were obtained using reference fuel A as describedpreviously with respect to Table I.

Table II Grams of Octane Additive nickel per number gallonBis(cyclopentadienyl nickel) propyne.. 0 99.9 1.0 101. 4 Bis(cyclopentadienyl nickel) heXyne-3 0 99.8 0.2 110. 0

As shown by the above table, compounds of my invention prove extremelyeffective as supplemental antiknocks 14 when tested in the modified CFRinjector engine. As will be noted by a comparison of Tables I and II,the modified injector engine rating is extremely sensitive.Consequently, the increase in octane number, noted in this type of test,is larger than would generally be observed in the Research Method usedin establishing the data for Table I.

A further use for my compounds is in gas phase metal plating. In thisapplication, the compounds are thermally decomposed in an atmosphere ofa reducing gas such as hydrogen or a neutral atmosphere such as nitrogento form metallic films on a sub-strate material. These films have a widevariety of applications. They may be used in forming conductive surfacessuch as employed in a printed circuit, in producing a decorative effecton a substrate material, or in applying a corrosion-resistant coating toa sub-strate material.

The compounds of my invention also find application as additives todistillate fuels used in home heating, and as additives to lubricatingoils and greases to impart improved lubricity characteristics thereto.Further, my compounds may be incorporated in paints, varnish, printinginks, synthetic resins of the drying oil type, oil enamels and the liketo impart improved drying characteristics to such compositions. Otherimportant uses of my compounds include their use as chemicalintermediates in the preparation of metal-containing polymericmaterials. Also, some of the metallic derivatives of my invention can beemployed in the manufacture of medicinals and other therapeuticmaterials, as well as in agricultural chemicals such as, for example,fungicides, defoliants, growth regulants, and the like. In addition tothe use of my compounds in reducing smoke and soot when used asadditives in distillate fuels used in home heating, they are also usefulas additives to jet fuels and diesel fuels in reducing smoke and soot.

Having fu-lly defined the novel compounds of my invention, their mode ofpreparation and their manifold utilities, I desire to be limited onlywithin the lawful scope of the appended claims.

I claim:

1. Organometallic compounds represented by the formula;

QCECQ' CyNiNiCy in which Q and Q are selected from the group consistingof hydrogen and univalent hydrocarbon radicals containing from one toabout 10 carbon atoms, Cy and Cy are cyclomatic hydrocarbon groupshaving 5 to about 13 carbon atoms each of which donates five electronsto the nickel atom for bonding, and each of the two nickel atoms in themolecule achieves the electron configuration of krypton.

2. The compounds of claim '1 wherein Q is hydrogen and Q is an alkylgroup containing from one to about 6 carbon atoms.

3. The compounds of claim 1 wherein Q and Q are alkyl groups containingfrom one to about 6 carbon atoms.

. Bis(cyclopentadienyl nickel) acetylene.

. Bis(cyolopentadienyl nickel) propy-ne.

. BisQcyclopentadienyl nickel) hexyne-S.

. Bis(-cyclopentadienyl nickel) pentyne-l.

. Bis(cyclop-entadienyl nickel) butyne-2.

. Bis(cyclopentadienyl nickel) phenylacetylene.

10. A process comprising reacting a compound having the formula Cy Niwherein Cy is a cyclomatic hydrocarbon group having 5 to about 13car-bon atoms with an acetylenic compound having the formula:

QCECQ' wherein Q and Q are selected from the group consisting ofhydrogen and univalent hydrocarbon radicals containing from one to about10 carbon atoms.

11. Process for the preparation of bisQcyclopentadienyl nickel)acetylene, said .process comprising reacting nickelocene with acetylene.

12. Process for the preparation of bis(cyclopentadienyl V ocene withpentyne-l.

'15. Process for the preparation of bis(cyclopen-tadienyl nickel)butyne-Z, said process comprising reacting nickelocene with butyne-2.

16. Process for the preparation of bis(cyc1opentadienyl nickel)phenylacetylene, said process comprising reacting nickelocene withphe-nylacetylene.

References Cited in the file of this patent UNITED STATES PATENTS2,875,223 Pedersen et a1. Feb. 24, 1959 2,898,359 Leedham et a1. Aug. 4,1959 2,901,336 Brown Aug. 25, 1959 2,918,360 Lauer Dec. 22, 1959 OTHERREFERENCES Dubeck: J.A.C.S. Jan. 20, 1960, vol. 82, No. 2. Hubel et al.:J. Inorg. Nucl. Chem, March 1959, v0

V 9, pp. 204 to 210.

T iln'ey-B-assett et -al.: J.A.C.S., volume 81, Sept. 5, 1959, p.4757-4758?

1. ORGANOMETALLIC COMPOUNDS REPRESENTED BY THE FORMULA: